feat: Moves gumps out of the core (#1916)

> [!Important]
> **Developer Note**
> This code change will **completely move gumps out of the core**


### Summary

- Adds `GetGumps()` convenience which exposes methods to Find/Close/Send multiple gumps. This helper is a performance improvement by eliminating the Dictionary<Player, List> lookup for gumps.

Projects/UOContent/Engines/Help/PagePromptGump.cs

@@ -8,6 +8,8 @@ public sealed class PagePromptGump : StaticGump<PagePromptGump>
     private readonly Mobile _from;
     private readonly PageType _type;
 
+    public override bool Singleton => true;
+
     public PagePromptGump(Mobile from, PageType type) : base(0, 0)
     {
         _from = from;
@@ -31,12 +33,6 @@ public sealed class PagePromptGump : StaticGump<PagePromptGump>
         builder. AddButton(405, 355, 2073, 2072, 0); // Cancel
     }
 
-    public override void SendTo(NetState ns)
-    {
-        _from.CloseGump<PagePromptGump>();
-        base.SendTo(ns);
-    }
-
     public override void OnResponse(NetState sender, in RelayInfo info)
     {
         if (info.ButtonID == 0)